Abstract Background The Milan Ultrasound Criteria (MUC) were developed to assess disease activity in ulcerative colitis (UC) based on bowel wall thickness (BWT) and Colour Doppler signal (CDS), using the formula MUC= 1.4 × BWT (mm) + 2 × CDS (0= absent; 1 = present)1. A MUC 6.2 identifies patients with a Mayo endoscopic subscore (MES) 1. Although the MUC have been externally validated, existing studies were limited by small sample size and single-centre design2,3. We aimed to apply and validate the MUC in a large, multicentre, real-world Italian cohort using endoscopy as the reference standard. Methods This multicentre prospective study included consecutive UC patients undergoing both intestinal ultrasound and endoscopy. Endoscopic activity was defined as MES 1, and endoscopic remission as MES 0–1. The original coefficients of BWT and CDS (1.4 and 2.0, respectively), derived from the multivariable analysis in the derivation study, were applied to calculate the MUC. Diagnostic performance was assessed using receiver operating characteristic (ROC) analysis to determine the area under the curve (AUC), sensitivity and specificity. Results A total of 181 UC patients (median age 41 years, IQR 29-56; 94 males) were enrolled contributing 251 paired intestinal ultrasound and endoscopy assessments. Among these, 214 showed endoscopic activity (MES 1) and 37 indicated endoscopic remission (MES 0–1). ROC analysis confirmed MUC 6.2 as the optimal cut-off to discriminate endoscopic activity from remission, with an AUC of 0.911 (95% CI 0.869 - 0.943). In this large validation cohort, a MUC 6.2 achieved a sensitivity of 87.9% (95% CI 82.7 - 91.9) and a specificity of 83.8% (95% CI 68 - 93.8). Conclusion In this large multicentre Italian cohort, the MUC demonstrated excellent diagnostic accuracy in differentiating endoscopic activity from remission, confirming its validity as a non-invasive monitoring tool in UC. These findings support the incorporation of the MUC into routine point-of-care ultrasound assessments and into future clinical trials in UC. References: 1. Allocca M, Dell’Avalle C, Furfaro F, et Al. Early Intestinal Ultrasound Predicts Long-Term Endoscopic Response to Biologics in Ulcerative Colitis. J Crohns Colitis. 2023 Nov 8;17(10):1579-1586. 2. Allocca M, Filippi E, Costantino A, et Al. Milan ultrasound criteria are accurate in assessing disease activity in ulcerative colitis: external validation. United European Gastroenterol J. 2021 May;9(4):438-442. 3. Innocenti T, Rocco C, Scarallo L, et Al. Systematic Review of Available Intestinal Ultrasound Scores for Inflammatory Bowel Disease and Update on Validation Studies. Inflamm Bowel Dis. 2025 Sep 20:izaf183. Conflict of interest: Dr. Allocca, Mariangela: Personal Fees: consulting fees from Nikkiso Europe, Mundipharma, Janssen, Abbvie, Pfizer, Ferring, Galapagos, Sandoz, Lilly and Alfasigma Zilli, Alessandra: Personal Fees: Speaking and consulting fees from Tillotts, Galapagos, Abbvie, Takeda, Janssen, Alfasigma, Sandoz, Lilly, Pfizer Terracciano, Fulvia: No conflict of interest Cataletti, Giovanni: No conflict of interest Bezzio, Cristina: No conflict of interest Fraquelli, Mirella: No conflict of interest Calabrese, Emma: none Zorzi, Francesca: No conflict of interest Rispo, Antonio: None De Bernardi, Alice: No conflict of interest Furfaro, Federica: Grant: IG-IBD Personal Fees: Pfizer, Biogen,J & J, Abbvie, Amgen, Janssen Matichecchia, Cosimo Simone: No conflict of interest Faggiani, Ilaria: No conflict of interest D’Amico, Ferdinando: No conflict of interest Radice, Simona: No conflict of interest Marra, Antonella: No conflict of interest Saibeni, Simone: No conflict of interest Caprioli, Flavio: Flavio Caprioli served as consultant to: Abbvie, Amgen, MSD, Takeda, Janssen, Roche, Celgene, Bristol-Meyers Squibb, Galapagos, Gllead, Pfizer, Mundipharma, Biogen, Ferring, Eli-Lilly, Nestlè, Lionhealth, AlfaSigma, Dr Falk, Celltrion, Abivax. He received lecture fees from Abbvie, Ferring, Takeda, Allergy Therapeutics, Janssen, Pfizer, Biogen, Sandoz, Tillotts Pharma, Vifor Pharma, AlfaSigma, Celltrion, Eli-Lilly. and unrestricted research grants from Giuliani, Sofar, MSD, Takeda, Abbvie, Celltrion, Pfizer, Actial. Maconi, Giovanni: Personal Fees: Abbvie, Arena Pharmaceuticals, Alfa-Wasserman, Fresenius-Kabi, Gilead, Janssen Cilag, Roche Non-financial Support: Takeda, Abbvie, Alfa-Wasserman Castiglione, Fabiana: Honoraria from: Takeda, AbbVie, Celltrion, Johnsson Johnsson, Cadigroup, Sandoz, Pfizer, Lilly, Lionhealth, Nestlè Armuzzi, Alessandro: Consulting fees from AbbVie, Abivax, Alfa Sigma, Astra Zeneca, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Celltrion, Eli-Lilly, Enthera, Ferring, Galapagos, Gilead, Giuliani, Janssen, Lionhealth, MSD, Nestlé, Pfizer, Protagonist Therapeutics, Roche, Samsung Bioepis, Sanofi, Sandoz, Takeda, Teva Pharmaceuticals, Tillots Pharma Speaker’s fees from AbbVie, Abivax, AG Pharma, Alfa Sigma, Biogen, Bristol-Myers Squibb, Celltrion, Eli-Lilly, Ferring, Galapagos, Gilead, Janssen, Lionhealth, MSD, Novartis, Pfizer, Roche, Samsung Bioepis, Sandoz, Takeda, Teva Pharmaceuticals Research support from Biogen, MSD, Takeda, and Pfizer Non-financial support from Abbvie, Janssen, MSD, Pfizer, Takeda Fiorino, Gionata: Personal Fees: Takeda, Johnson & Johnson, Alfasigma, AbbVie, Celltrion, Pfizer, Sandoz, Abivax, Lilly, STADA Danese, Silvio: Personal Fees: AbbVie, Alimentiv, Allergan, Amgen, Applied Molecular Transport, AstraZeneca, Athos Therapeutics, Biogen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Celltrion, Dr Falk Pharma, Eli Lilly, Enthera, Ferring Pharmaceuticals Inc., Gilead, Hospira, Inotrem, Janssen, Johnson & Johnson, Morphic, MSD, Mundipharma, Mylan, Pfizer, Roche, Sandoz, Sublimity Therapeutics, Takeda, Teladoc Health, TiGenix, UCB Inc., Vial, Vifor Lecture fees from Abbvie, Amgen, Ferring Pharmaceuticals Inc., Gilead, Janssen, Mylan, Pfizer, Takeda
Wilkens et al. (Thu,) studied this question.